diff --git a/lib/compiler.js b/lib/compiler.js
index 1752f3d..839b58e 100644
--- a/lib/compiler.js
+++ b/lib/compiler.js
@@ -52,7 +52,7 @@ function runTypeScriptCompiler(logger, projectDir, options) {
 			nodeArgs.push('--inlineSourceMap', '--inlineSources');
 		}
 
-		if (this.shouldPreserveWatchOutput(typeScriptVersion)) {
+		if (shouldPreserveWatchOutput(typeScriptVersion)) {
 			nodeArgs.push('--preserveWatchOutput');
 		}